Frank Lampard has warned England could be heading out of the World Cup if they underestimate second-round opponents Ecuador in Stuttgart on Sunday.

The Chelsea midfielder knows England will be made red-hot favourites to clinch a place in the quarter-finals after avoiding Germany and being paired with the surprise team of the tournament.

But Lampard has been sufficiently impressed with Ecuador's performances against Poland and Costa Rica to know they will pose a genuine challenge to Sven-Goran Eriksson's side.

Ecuador lost 3-0 to Germany in their final group match but left out five members of their first-choice XI after having already qualified for the next phase.

Lampard said: "Ecuador are not to be underestimated. They have been well beaten by Germany but the two performances they put in beforehand were very good.

"I think we fully understand now at his level that you don't get any easy games especially in the last 16 so we will have to be right on top form.

"There will be pressure because we are expected to win - but then we've been expected to win all the games so far so there is nothing new there.

"But this is important now because this is the real business end because you know if you lose, you are out.

"Ecuador will be as desperate to get through to the quarter-finals as we are. We have to understand people will talk us up as favourites but if we are not on top of our game then we will make it very tough.

"We have to make sure we are at our game and ready to come out of the traps from the start."

Lampard added: "If you go through this round, you know you are not that far away from the final. I know you are playing big teams then but that's the nature of the World Cup.

"We know we are going to play stronger teams along the way but I think we will cope with that and respond in a positive way to the challenge."

Lampard was impressed with the contribution of Owen Hargreaves in the holding midfield role, in what was his first England start for 27 months, and the skill and vitality of Joe Cole on the left flank.

He said: "Owen did well. He was picking up a lot of balls in front of the back four and giving me a bit of licence to go forward and try to get into the box and I enjoyed that.

"I think in the first half everything worked well. We were getting the ball out to Joe Cole who was running at them causing them a lot of problems.

"Joe looked impressive. In the first half especially he was very good - and working hard as well - and that's what you need to get from Joe."

Lampard, who was 28 yesterday, again went close to scoring on several occasions and knows the midfielders have greater onus to find the net especially after Michael Owen's knee injury.

He said: "There is more responsibility on the midfielders to get goals and at the moment that is happening which is a good thing. Steven Gerrard has got two already and Joe Cole one.

"I'm yet to score in the tournament but I feel like it's coming so hopefully I can add to that midfield contribution."

But Lampard is also aware England need to tighten up at set-pieces after being punished by Marcus Allback and Henrik Larsson who scored in the 2-2 draw.

He said: "We know we didn't defend set-pieces as well as we should have done for the two goals they scored. We are not normally vulnerable in those situations. It has to be put right.

"I am not pointing fingers at anyone because we take credit and we take criticism altogether but the defending at set-pieces is something for all of us to look at ourselves and I think we will do that in the next few days."